The present invention relates to valves and more particularly to rotary valves.
Still further the present invention relates to rotary valves for reciprocating heat engines and particularly for internal combustion engine.
With particular reference to valves employed in internal combustion piston engines, known rotary valves have not been widely accepted as they have not provided the advantages of conventional valves in respect of simplicity of construction, cost of manufacture, oil consumption, durability and ruggedness.
A rotary valve arrangement is disclosed in U.S. Pat. No. 985,618 to Miller. The patent to Miller discloses a rotary valve including a valve housing formed integral with the head of the engine and which receives a valve rotor which communicates with the combustion chamber via an annular sealing ring generally coaxial with the port communicating with the combustion chamber. More particularly the patent to Miller relates to this annular sealing member and its configuration whereby under combustion pressures the sealing members is formed into sealing contact with the valve rotor. Rotary valves are also disclosed in U.S. Pat. Nos. 1,347,978 and 1,573,022, both to Wehr. The earlier patent to Wehr discloses a rotary valve assembly having a split housing to support a bush having a cylindrical inner surface to receive the valve rotor. This sleeve has a cylindrical outer surface eccentric with respect to the inner surface. The valve rotor communicates with the combustion chamber by means of a port extending through the sleeve and part of the housing. It should be particularly noted that the split housing is mounted on the cylinder and forms the head of the engine. The second patent to Wehr is a modification of the device disclosed in his earlier patent, and more particularly describes a means of biasing the sleeve into sealing contact with the valve rotor. The U.S. Pat. No. 1,887,997 to Cross, also relates to a rotary valve arrangement and in particular relates to an annular sealing element which surrounds the port exiting from the combustion chamber and which sealingly engages the valve rotor. This annular sealing member is generally coaxial with the port extending from the combustion chamber. U.S. Pat. No. 2,048,134, describes a rotary valve arrangement with the rotor being supported by a housing consisting of two portions which are spring biased together so as to engage the valve rotor. An annular sealing element surrounds the port exiting from the combustion chamber and also sealingly engages the valve rotor. U.S. Pat. No. 1,997,133, to Cross, is an improvement on Cross's earlier Pat. No. 1,887,997, and particularly relates to the annular sealing element surrounding the port exiting from the combustion chamber and sealingly engaging the rotor. It is again pointed out that this annular sealing element is generally coaxial with the port exiting from the combustion chamber. U.S. Pat. No. 2,158,386, describes a rotary valve arrangement having a hollow housing within which is received a sleeve 25 supported in a spaced relationship relative to the housing. The sleeve defines a cylindrical passage which receives the valve rotor and the sleeve is attached to the cylinder head. More particularly this patent describes a method of constructing the sleeve particularly when the sleeve is constructed of two parts whereby the two parts are resiliently biased together by means of springs. U.S. Pat. Nos. 2,853,980 and 3,871,340, to Zimmerman, describe a rotary valve arrangement with the head of the engine having a cylindrical passage to receive the valve rotor, formed integral with the head is a resilient support for the rotor and the arrangement further includes an annular sealing element which surrounds the port communicating with the combustion chamber. This annular sealing element is generally coaxial with the port and engages the valve rotor. U.S. Pat. No. 3,990,423, to Cross, describes a rotary valve arrangement with the valve rotor supported in a two part housing with one of the housing parts forming the cylinder of the engine. The two part housing is biased together by means of a spring arrangement with the valve rotor communicating with the combustion chamber by means of a port. An annular sealing element is located around the port and sealingly engages the valve rotor. These known rotary valves have suffered from the drawbacks of most rotary valves in that they are generally costly to manufacture and lack durability and ruggedness and in particular consume excessive amounts of oil or require external oil control methods by reason of the fact that oil used in lubricating the valve rotor is relatively free to enter the combustion chamber of the engine.